Apparatus for forming medicinal tablets.



H. E. WHITAKBR & J. M. MAUDONALD.

APPARATUS FOR FORMING MEDICINAL TABLBTS.

APPLICATION PILBD MAR. B, 1908. 1,102,374 Patented July 7, 1914.

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H. E. WHITAKBR & J. M. MAUDONALD.

APPARATUS FOR PORMING MEDICINAL TABLETS.

APPLICATION FILED MAB. 9, 190B.

Patented July 7, 1914.

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,' E` STATES PATET FFIDE- HENRY E. WHITAKER AND JAMES M. MACDONALD, OFDETROIT, MICHIGAN, ASSIGN- ORS T0 PARKE, DAVIS t COMPANY, 0F DETROIT,MICHIGAN, A CORPORATION `OF` MICHIGAN.

APPARATUS FOR FORMING MEDICINAL TABLETS.

Specification. of Letters Patent.

Application filed March 9, 1908.

Patented July 7, 1914!. sei-iai No. 420,097.

To all 107mm 'it may] concern Be it known that we, HENRY E.' lll/'Hirnitin: and Jairns M. MACDONALD, citizens of the United States oit'America, residing at Detroit, in the county of lVayne and State oitlyliichigan, have invented certain new and nse'tul Improvements inApparatus for Forming Medicinal Tablets, of which the following is aspecification, reference being had thereinto the accompanying drawings.

rlhe invention relates to machines for forming tablets, and it is thespecial object of the invention to obtain a construction which isadapted for forming medicinal tablets either friable or hard compressed.

To this end the invention consists in certain features of constructionas hereinafter set forth.

In the drawings- Figure 1 is a vertical longitudinal section through themachine; Fig. 2 is a cross-section substantially on the line ot Figil,certain `parts being o-mitted. y

In the present stateo'f the art medicinal tablets` of the soft riablevariety ai'e formed by a hand process, while the compressed tablets `areformed mechanically. The hand process is one necessitating' the` mixingof the dry ingredients with alcohol to :form a plastic compound, theiilling of the perforated mold plates with this plastic substance by theuse of a spatula, the drying and har.- dening of the material in themold cavities by dusting in dry powder over the surface of the plate andscraping it in with the spatula, and inally the ejection of the mold edtablets from the plates. This process is a slow one, requiring a certaindegree of skill on the part of the operator and necessitating the use ofalcohol as amoistening agent. On the other hand, the compressed tablets,while they may be 'formed by mechanically driven and automatically operated presses, require `for their manufacture' a granulated materiah andthis necessitates a long and expensive process of the treat nient of theingredients before the material is ready forl the press.

With the machine forming the subject matter of the present invention thetablets may be formed from the mixed ingredients by slight moistening ofthe mixed'dry materials, and for the moistening agent water may beemployed,`instead of alcohol.

Broadly considered, the machine comv prises means -tor distributing thematerial over the mold plates, together with means :for niecluinicallypressing the distributed material into the mold cavities and` forscraping ott' from the surface the surplus material.

The machine further comprises mechanisin for ejecting the tablets fromthe mold cavities aiiih'u'licre the'eoiupressed tablets areto be formed,further includes compress' ing dies and operating ii'iechanisnitherefor.

One oit' the difficulties encountered in the manipulation ot' thematerials oi which the tablets ai'e formed is the tendency to adhere i.

saine degree of compression. To ineetthese cond1t1ons,the machinecomprises as` one of its essential features mechanism 'toi' moving ablade a'portion oil which is inclined over the surface of the mold plateupon which the tablet `.material has been deposited while said,

plate is resting upon a bed or tabl e, the operation of the blade beingto simultaneously force the material into the mold cavities and to seraic'o'fl the sur ilus material. .ln ier` yforming this function there isa tendency to coniifiress the `material to a greater degree upon theside ot' the mold cavity toward which the inclined blade `is moved, andto avoid this result a second bladehavingan oppositely inclined portionis preferably employed, this being moved over the plate in reversedirection. the blades and the mold plate may be accomplished indifferent ways. but preferably is effected by mounting' the blades uponrevoluble members and by feeding the plates` beneath said revolublemembers.

ln detail A is a suitable frame or bed provided with guii'leways B forthe movable mold plates C. These plates are fed along the guides bysuitable feeding mechanism, such as the `i'olls D D', which frictionallyengage the plates as they are intro duced at one end of the machine.feeding them over the bed and propelling the plates to advance as theyare disengaged from the rolls. Adjacent to the i'olls D D is ai'- rangeda hopper, or other' receptacle, lil

The relative movement of` containing the material forming the tablets.This material has been previously mixed and moistened and the hopper Epreferably contains an agitator, such as the revoluble member F, forassisting the uniform deposit of the material on the mold plates. Beyondthe member F is a filling and distributing roll Gr which gages theheight of the material deposited on the plates, and also presses it intothe mold cavities. The surface of this roll is of any suitable material,such for instance as celluloid, to which the moistened material will notreadily adhere.

H and l are two oppositely revoluble shafts extending across the bedabove the path of the mold plates and journaled in suitable bearings inthe frame. Each of these shafts has secured thereto a series of radiallyextendingplates J, these being preferably formed of resilient materialand being preferably also slightly curved. The blades carried by theshafts H travel in the same direction as the mold plates, but at ahigher rate of speed, while the blades on the shaft l travel in theopposite direction. Thus the former will press the material which coversthe surface of the plates downward and into the mold cavities, and willthen scrape over the surface of the plates to remove the surplusmaterial, throwing it forward or in the direction that the mold plate istraveling. The blades upon the shaft I have a similar action upon thematerial which has been thrown forward by the other blades, and thecombined action of the two sets of blades is to accumulate the surplusmaterial in a triangular pocket between the shafts H and l. The materialis prevented from being thrown over the shafts H and and the blades arealso cleaned by Scrapers K, which are arranged to bear upon each of theblades, as they rotate to disengage any adhering material therefrom.

The plates after passing beneath the shaft I are fed forward at anaccelerated speed by a pair of feed rollers L L, and this is for thepurpose of permitting each plate to remain stationary for an intervalduring which the tablets are ejected. The ejector mechanism comprises avertically reciprocating head M, which is provided with downwardlyextending pins N thatA register with the mold cavitiesy in each of themold plates C, during the interval in which it is stationary beneath thehead M. The descent of this head will cause the pins N to force thetablets downward from the mold cavities, and at this point the bed ofthe machine is cut away to permit the disengaged tablets to drop upon areceiving plate or carrier O.

Vhere oval or other fashioned tablets are to be formed this operation iseffected while the material is still in the mold cavities and after theplates have passed beyond the Scrapers. lf desired, this formingmechanism may be combined with the ejector mechanism, the head M havinga portion M thereof for holding one of the compression dies and a secondcompression die P being arranged beneath the plate and being movedforward as the head M is moved downward.

Any suitable form of gearing may be employed for driving the variousparts of the mechanism above referred to in proper timingrelation. Asshown, motion is first communicated to the main drive shaft Q, by asuitable belt engaging tight and loose pulleys upon this shaft. Thisshaft Q drives the rolls L L through the medium of a gear train R, anddrives the shafts H and T through a gear train S. The rolls D D aredriven through the gear train S and a sprocket and chain connection T,and the roll G is driven from the shaft of the roll D by a sprocket orbelt connection U. The ejector and compressor mechanism is operatedthrough a gear train V from the shaft Q, which drives a shaft W, havingeccentrics X and Y thereon, which are respective-ly connected to operatethe heads M and l.

In operation, the moistened material is placed in the hopper E and isdriven over the plates as they are fed forward by the rolls D D', whilethe roll G, which is preferably driven at the same speed as the plate,gages the depth of the deposit and presses it down to fill the moldcavities. is the plates continue their forward movement, they first passbeneath the shaft H and into the path of lthe rotating blades J carriedthereby. These blades are curved, as described, and rotate to press theconvex surface against the material on the plates forcing it downwardinto the mold cavities until the edge of the blade l comes in contactwith the upper surface of the plate C. The blade will then be caused toscrape over the surface of the plate, the resiliency of the material ofthe former permitting this operation. A similar action takes place asthe plates C are fed beneath the shaft l, the only difference being thatin the first casethe pressure exerted on the material is toward theforward side of the mold cavity and in the latter case toward the rearside thereof. The effect will be to produce a uniform density in allportions of the tablets, and the operation of the blade el on the shaftI will produce a smooth upper surface. The lower surface of the tabletis formed by sliding over the bed or table upon which the plates C aremoved, and thus when the ejector' mechanism is reached the tablets arein condition for disemqagement.`

lt is to be noted that the operations performed by this machine differfrom those of the usual hand processi ln the latter, the

i to dust dry powder over each face ofthe dry powder.

mold plate working it into the mold cavi-` ties with the spatula, and`thereby drying and hardening theitablets before they can be ejected. Intheoperationof the machine, the material hasbut a limited amount ofmoisture therein, so that it can only be forced into the mold cavitiesby the exertion of considerable i pressure. produced by the action ofthe blades and, as they are traveling at a higher rate of speed than themovement of the plate C, a series of these blades will successivelyoperate upon the material for each row of tablets. Thus, afterthecavities `are filled, and the surplus material scraped off, the tabletsare in condition to be immediately ejected without `requiring theintermediate step of dusting in The operation of the blades J J in theopposite direction causes the accumulation of a `quantity of thematerial therebetween, and to remove this material a transversely`evtending j screw conveyer or equivalent device Z is arranged betweenthe shafts H and I. This in operation will carry away the accumulatedmaterial which may be returned to the hopper E.

What we claim as our invention is:

l. In an apparatus for forming medicinal tablets, a mold. plate having aseries of mold cavities therein, a roll extending transversely of themold plate for depositing a uniform layer of material over the latter, ablade,`

and means for operating said blade to scrape and knead the material intothe mold cavities.

2. In an apparatus for forming medicinal tablets, a mold plate having aseries of mold cavities therein, means for depositing material upon saidplate, a plurality of revolving blades, a portion of said blades beinginclined in the direction of said blades travel for pressing andscraping the material into the mold cavities.

3. The combination with a mold plate having a series of mold cavitiestherein, of means for depositing the material upon said plate, means forscraping the material in opposite directions over said plate, and meansfor removing the surplus material accumulated by said scraping means.

l. The combination witha mold plate having a series of mold cavitiestherein, of a bed over which said plate is fed, means for depositingthematerial upon said plate, a pair of oppositely rotating members abovesaid bed, Scrapers carried by said rotating members and moved therebyacross said plate when moved over said bed to force the l material `on isaid This pressure is f each mold `depthlof theimaterial thus deposited,oppoplate into said mold cavities, and means for removing the surplus`material accumulated by said Scrapers,

5. The combination with a bed, of a series ofmold plates adapted to besuccessively fed over said bed, j each `plate being provided with` aseries of `mold cavities, means for de-` positing the material upon saidplates, a revolving `blade forforcing the deposited material into themold cavities, and for removing the surplus material, and an ejector foridisengaging the molded tablets from said plates` 6. Thecombination witha bed, of a series of mold platesZ each provided with a series of moldcavities, means for feeding 1 said.

mold plates successively ovei'isaid bed, means for depositingr materialon the surface of plate, a `gage for determiningthe sitely revolvingblades for pressing and scraping the material into `the mold cavities,and means for ejecting the molded tablets.

` 7. The combination with a mold plate having a series of mold cavitiestherein, of means for depositing material upon said plate, a roll forpressing thejmaterial against the plate and into the mold cavitiesthereof, a blade having an inclined portion, and means for moving saidblade over the surface of said plate to further press the material intothe mold cavities and removing the surplus material from the surface ofthe plate.

8. The combinationwith a mold plate having `a series of aperturesextending therethrough, of a bed, means for feeding said plate over saidbed, means for depositing the material on the surface of said plate,means for pressing the deposited material against the plate to force itinto the mold cavities thereof, means for drawing an inclined scraperover the plate to further force the material into the mold cavities andto remove the surplus material, a forming die for fashioning the moldedmaterial while still in the mold cavities of said plate, and an ejectorfor disengaging the completed tablet.

`9. The combination with a bed or table, of a mold plate having a seriesof mold cavities therein, means for feedingsaid plate over said bed or`table, means for depositing material upon said plate, a roll forpressing the deposited material against said plate and into the moldcavities thereof and for gaging the depth of the material upon theplate, a rotary member having a series of Scrapers successively drawnover the surface of said plate, a forming die for fashioning the tabletsWhile in the mold cavities and an ejector for disengaging said tablets.

10. The combination With a mold plate having a series of mold cavitiestherein, of means for depositing a uniform layer of material over saidplate, a series of revolving means for feeding said. mold plate acrossthel path of movement of said yblades and transverse thereto, for thepurpose described.

l2. The combination With a movable mold plate haing a series of moldcavities therein, of a revolving blade partially inclinedl in thedirection of travel of said blade for pressing and scraping thelmaterial into the mold l cavities.

13. In an apparatus for forming medicinal tablets, a mold plate having aseries of l Imold cavities therein, a plurality of revolving bladespartially inclined in the direction of travel `of said blades forpressing and scrapingthe material into the mold cavities.

lll. In anapparatus for forming medicinal tablets, a mold "plate havinga series of mold cavities therein, means for depositing a uniform layerof material over said plate, a blade for forcing the material into themold cavities, means for moving said blade over the surface of saidplate in inclined relation thereto, and an elector for disengaging thetablets from .the mold cavities.

In testimony whereof We affix our signaytures in presence of tivoWitnesses. Y l

HENRY E. WHITAKEB. 'JAMESM- MACDONALD. Vitnesses to both signatures:

NELLIE KINSELLA, JAMES?. BARRY.

ACopies of this patent may be obtained for ve cents*l each, byaddressing the Commissioner of latents,

Washington, I). G."

